simplify tokens (known variable values in conditions)

src/tokenize.cpp

@@ -1933,10 +1933,10 @@ bool Tokenizer::simplifyKnownVariables()
                     if (tok3->varId() == varid)
                         break;
 
-                    // Replace variable with numeric constant..
-                    if (Token::Match(tok3, "if ( %varid% )", varid))
+                    // Using the variable in condition..
+                    if (Token::Match(tok3, "(|==|!=|<|<=|>|>= %varid% )|==|!=|<|<=|>|>=", varid))
                     {
-                        tok3 = tok3->next()->next();
+                        tok3 = tok3->next();
                         tok3->str(value.c_str());
                         ret = true;
                     }

test/testmemleak.cpp

@@ -1834,7 +1834,7 @@ private:
     {
         check("void foo()\n"
               "{\n"
-              "    char *str = 0;\n"
+              "    char *str = malloc(10);\n"
               "    free(str);\n"
               "    char c = str[10];\n"
               "}\n");

test/testtokenize.cpp

@@ -89,6 +89,7 @@ private:
         TEST_CASE(simplifyKnownVariables6);
         TEST_CASE(simplifyKnownVariables7);
         TEST_CASE(simplifyKnownVariables8);
+        TEST_CASE(simplifyKnownVariables9);
 
         TEST_CASE(multiCompare);
 
@@ -528,7 +529,7 @@ private:
         std::ostringstream ostr;
         for (const Token *tok = tokenizer.tokens(); tok; tok = tok->next())
             ostr << " " << tok->str();
-        ASSERT_EQUALS(std::string(" void f ( ) { int a ; a = 4 ; if ( g ( a ) ) ; }"), ostr.str());
+        ASSERT_EQUALS(std::string(" void f ( ) { int a ; a = 4 ; if ( g ( 4 ) ) ; }"), ostr.str());
     }
 
     void simplifyKnownVariables5()
@@ -620,6 +621,28 @@ private:
         ASSERT_EQUALS(std::string(" void foo ( ) { int i ; i = 23 ; ; abc [ 23 ] = 0 ; }"), ostr.str());
     }
 
+    void simplifyKnownVariables9()
+    {
+        const char code[] = "void foo()\n"
+                            "{\n"
+                            "    int a = 1, b = 2;\n"
+                            "    if (a < b)\n"
+                            "        ;\n"
+                            "}\n";
+        // tokenize..
+        OurTokenizer tokenizer;
+        std::istringstream istr(code);
+        tokenizer.tokenize(istr, "test.cpp");
+
+        tokenizer.setVarId();
+        tokenizer.simplifyKnownVariables();
+
+        std::ostringstream ostr;
+        for (const Token *tok = tokenizer.tokens(); tok; tok = tok->next())
+            ostr << " " << tok->str();
+        ASSERT_EQUALS(std::string(" void foo ( ) { int a ; a = 1 ; int b ; b = 2 ; if ( 1 < 2 ) ; }"), ostr.str());
+    }
+
 
 
     void multiCompare()